1. Field of the Invention
The invention relates to a roll up ramp system for loading and unloading machinery from a hauling vehicle; and more particularly, to a ramp system that can be rolled up for storage and unrolled to form a durable, rigid ramp capable of releasable attachment to the hauling vehicle.
2. Description of the Prior Art
Today's active society calls for the hauling and transporting of a variety of equipment and machinery, such as lawn mowers, snow blowers, snow mobiles, JET SKI™s (personal watercrafts (PWCs)), ATVs and the like. Loading machinery of this kind, which is generally heavy and cumbersome in nature, into a hauling vessel, such as a truck or wagon, is often times difficult and tiresome. To avoid actually lifting the machinery, which might require several persons, ramp structures are widely utilized. Foldable or collapsible ramp structures provide an especially convenient means for loading machinery into the hauling vessel. After the machinery is loaded into the vessel, the ramp structure can be folded or collapsed for storage.
Foldable or collapsible ramp structures heretofore disclosed and utilized are bulky by nature and design. That is to say, many of the foldable or collapsible ramps generally have multiple ramp spans or slats that interlock by way of ramp links or flexible straps. These ramp structures have common disadvantages. They are generally cumbersome to arrange in both the ramp and folded configurations, and they are heavy. Still other designs utilizing linking configurations that lock to form bridges or ladders provide inadequate support. They are inconvenient to use, and are frequently incapable of supporting heavy loads. Furthermore, the ramp structures heretofore disclosed and utilized do not enable convenient secure attachment to the hauling vessel. For example, many of the ramp structures heretofore disclosed and utilized provide for securement of the ramp to the hauling vessel by way of a magnetic portion, a hinge, or through friction via application of a non-skid surface.
U.S. Pat. No. 5,347,672 to Everard et al. discloses a portable, stow-able knock-down ramp structure having several elongated tread plates, each provided with a leading edge and a trailing edge adapted to accommodate a cylindrical hinge rod so that the plates are pivotally connected together. The cylindrical hinge rod extends the full width of each plate and interconnects the leading edge of one plate with the trailing edge of another plate. U.S. Pat. No. 6,079,072 to Katsiri discloses a foldable and rigid space spanning structure including a frame assembly having a pair of spaced poles and a number of hinged sections aligned so that the poles and material can be folded in sections. The hinged sections are interconnected so that the structure folds with the plates piling on-top of one another, so that an accordion type folding configuration is accomplished rather than a roll-up configuration.
U.S. Pat. No. 6,722,721 to Sherrer et al. discloses a foldable pickup truck tailgate and ramp device having a series of rigid panels that are the same sized as a standard tailgate and being interconnected by hinge means so that the panels are capable of folding up, flat, into a pickup tailgate assembly configuration. The plates are linked so that they are folded in an accordion configuration as opposed to a roll-up configuration. U.S. Patent Application No. 2002/0088065 to Schmaltz et al. discloses a loading ramp structure having a plurality of relatively small rectangular links joined end to end to form a desired length and adapted to form a rigid ramp and to be rolled-up for storage. The vertical edge of each rectangular link in the Schmaltz et al. structure must be carefully aligned with the next adjacent link to produce rigidity sufficient for a useable ramp. None of these references disclose a ramp configuration that is comprised of a plurality of links formed of a lightweight rod construction that enables the ramp to be lightweight and easily rolled for storage.
Various foldable or collapsible ramp structures heretofore disclosed and utilized have multiple ramp spans or slats that interlock by way of ramp links or flexible straps. These ramps have a tendency to be bulky and heavy due to the nature of the links utilized in the configuration. In particularly, U.S. Pat. No. 6,463,613 to Thompson discloses a portable ramp having a central load bearing portion formed by several light weight, transversely positioned slates that are pivotally connected to one another by several flexible straps. A pair of strong, light weight braces rotates into a longitudinal position along the ramp sides to form rigid support of the central ramp portion. U.S. Pat. No. 6,643,878 to Schmaltz et al. discloses a loading ramp device which rolls up for convenient storage and is comprised of a plurality of relatively small rectangular links that are jointed end to end to form a ramp that can be rolled up for storage.
Chain linking configurations that link and lock to form ladders, bridges, or chains have heretofore been disclosed and utilized, however, theses apparatuses do not provide support and ready convenience, and may not be capable of supporting heavy loads. In such configurations, the vertical edge of each link must be carefully aligned with the next adjacent link to produce rigidity sufficient for a useable ramp. U.S. Pat. No. 288,455 to J. K. Landes provides a folding ladder formed by a series of sections pivoted to each other by rungs and having spring-hooks or clamping-frames for locking the sections together to form a ladder. U.S. Pat. No. 1,004,575 to Jones discloses a flat link chain having aligning elements that are hingedly connected together by pins that are adapted in use to cooperate with notched out parts on each of the elements. U.S. Pat. No. 1,570,014 to Stevens discloses a sprocket chain having central links with pivot openings and side links which are held in connection with the central links by pivot pins in the usual manner. U.S. Pat. No. 2,424,320 to Kilboum provides a chain having parallel selvedge chains built up of flat, “FIG. 8” form pressed steel links that are pierced with a pivot hole and having cross bars which extend across from one selvedge chain to the other. U.S. Pat. No. 2,602,345 to Braumiller discloses a chain link and chain device formed therewith having side links with a semicircular projecting nose connected to axial openings of rollers using rivet pins and is configured so that when the chain is straightened resistance to flexing in one direction is achieved. U.S. Pat. No. 3,586,393 to Myers discloses a conveyor structure including a pair of chains having a plurality of links in the form of shoes, cross-pins and side links that are connected to and carried by the cross-pins. U.S. Pat. No. 4,024,595 to Brown discloses a linkage bridge consisting of a plurality of links rotate-ably coupled in an end-to-end relationship to form an elongated structural platform with a rotational stop between each adjacent link. None of these references disclose a ramp configuration that is comprised of a plurality of links formed of a light-weight rod construction that enables the ramp to be lightweight and easily rolled for storage.
Significantly, none of the foldable ramps or chain, ladder, or bridge structures provides a rolled up configuration that is capable of supporting heavy loads when in the straight or ramp formation, and which is additionally capable of being rolled up for storage. None of the ramps disclosed or utilized provide a ramp structure that is capable of handling heavy loads associated with equipment, including lawn mowers, JET SKI™s (versonal watercrafts (PWCs)), snowmobiles, ATV s and the like.
For the foregoing reasons, there exists a need in the art for a ramp system capable of being readily rolled up for convenient storage which, when unrolled, readily forms a ramp having strength sufficient to carry heavy loads. Specifically, there exists a need in the art for a roll up ramp system that provides a durable rigid ramp configuration adapted for loading machinery, such as lawn mowers, snow blowers, JET SKI™s (personal watercrafts (PWCs)), snowmobiles, ATV s and the like, into a hauling device, such as a truck. Additionally, there is a need in the art for a roll up ramp system having a plurality of links interconnected to form a roll up ramp that is provided with rotation capability between each of the links so that the links can be rolled in one direction on top of one another to from a rolled up configuration when force is applied. Moreover, there is a need in the art for a ramp system capable of achieving a ramp configuration with exertion of minimal force. For the forgoing reasons there exists a need in the art for a roll up ramp system that is lightweight, strong, conveniently stored in a rolled up condition and readily deployed in an unrolled, ramp-like configuration to facilitate loading and unloading equipment from a hauling vehicle.